My half diagonal is 538·5465, and ratio 10 to 9, gives 484·69 British feet for the altitude.
I have mentioned the above to show how very nearly these ratios agree with my exact ratio of 21 to 34 half base to apothem.
| Fig. 11. Cephren. | Fig. 12. Cephren. |
Figures 11 and 12 show the ratios of Cephren, viz., half base to apothem, 20 to 33 exactly, and half base, altitude, and apothem respectively, as 80, 105, and 132, very nearly.
Also half diagonal, altitude, and edge, practically as 431, 400, and 588.
| Fig. 13. Mycerīnus. | Fig. 14. Mycerīnus. |
Figures 13 and 14 show the ratios of Mycerinus, viz., half base to apothem, 20 to 32 exactly, and half base, altitude, and apothem respectively, as 20, 25, and 32 very nearly.
Also full diagonal to edge as 297 to 198, nearly. A peculiarity of this pyramid is, that base is to altitude as apothem is to half base. Thus, 40 : 25 :: 32 : 20; that is, half base is a fourth proportional to base, apothem, and altitude.